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This European Standard, published in 1996, was prepared by
the European Committee for Standardization (CEN) "in response
to the growing demand to protect people from the risks of vibration
damage caused by exposure to hand-transmitted vibration."
All member countries were required to implement ISO 10819
as a national standard by December 1996. Countries which are
members of CEN are Austria, Belgium, Denmark, Finland, France,
Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
The standard furnishes the technical information needed for
laboratory testing and measurement of the vibration transmissibility
of gloves. Measurements are made in the palm of the hand and
do not include the fingers. The standard notes that a different
measurement procedure will be needed to make measurements at
the fingers.
The introduction to the standard states: "Within the
current state of knowledge, gloves do not provide significant
attenuation in the frequency range below 150 Hz. Some gloves
may provide amplification in this frequency range. . .However,
it must be emphasized that an important purpose of gloves is
to keep the hands warm and dry, as this may help to limit some
vibration-induced effects".
1. SCOPE
This standard defines a "screening test" for vibration
transmission to the palm of the hand through a handle vibrating
in the frequency range of 31.5 Hz to 1250 Hz. "The transmissibility
of vibration is measured and reported for two input spectra,
which are representative of the vibration of some tools and may
be reported as a function of frequency."
The standard notes that it does not assess the health risk
resulting from vibration.
2. NORMATIVE REFERENCES
Throughout the standard, reference is made to previous European
standards which contain related information and data. They include:
EN 420
General requirements for gloves
ENV 25349
Mechanical vibration - Guidelines
for the measurement and the assessment of human exposure to hand-transmitted
vibration (ISO 5349:1986)
ENV 28041
Human response to vibration - Measuring
instrumentation (ISO 8041:1990)
EN 61260
Electroacoustics - Octave-band and
fractional-octave-band filters
(IEC 1260:1995)
ISO 2041
Vibration and shock - Vocabulary
ISO 5805
Mechanical vibration and shock affecting
man - Vocabulary
3. DEFINITIONS
The definition of transmissibility used
in this standard is:
"The ratio of the accelerations
measured at the surface of the hand and at the reference point.
Transmissibility values greater than 1 indicate that the glove
amplifies the vibration. Values lower than 1 indicate that the
glove attenuates the vibration."
4. SYMBOLS AND ABBREVIATIONS
This section defines those used in the
standard.
5. MEASURING PRINCIPLE AND EQUIPMENT
Gripping force and feed force are measured
using a "shaker" excitation system. These measurements
are made at the surface of the handle and inside the glove between
the hand and glove. "The vibration transmissibility of the
glove is calculated as the difference in vibration transmissibility
from handle to hand with and without the glove." Because
the gripping and feed force of the shaker are related to each
other, the values of the two forces are displayed continuously
so the operator can adjust them to the required values.
The measuring equipment includes a frequency
analyzer, preferably twin channel (narrow band and one-third
octave band), two transducers and two channels of measuring equipment.
Additional measurement specifications
are for method of transducer mounting at handle and hand, frequency
analysis, gripping force measuring system, feed force measuring
system, vibration excitation system, geometrical characteristics
and performance.
6. MEASUREMENT CONDITIONS AND PROCEDURE
Test subjects are specified as three
adults with hand sizes from 7 to 9. Three different gloves should
be tested: one for each subject. Other specified conditions are:
gripping force: to
be maintained at 30 N (+-) 5 N throughout test
feed force: displayed continuously
and maintained at 50 N (+-) 8 N
room temperature:
20 degrees C (+-) 5 degrees C
humidity:
shall be below 70 per cent and shall be reported
conditioning of gloves: stored at specified temperature for at least
30 minutes and worn by subject for at least three minutes before
testing
fitting of gloves: size shall be chosen according to EN 420 (General
requirements for gloves)
test period: at
least 30 seconds for weighted measurements or third-octave band
analysis; shall allow averaging of at least 60 spectra if constant
bandwidth analysis is applied
The posture of the test subject-operator
is carefully defined, including the angle of the wrist and the
angle of the elbow, which should not touch the body during the
test.
The vibration signals to be measured
at the handle gripped by the subject fall into two spectra:
Vibration spectrum M: 31.5 Hz to 200
Hz (for third-octave bands (+-) 1 dB)
Vibration spectrum H: 200 Hz to 1250 Hz (for third-octave bands
(+-) 1 dB)
The mathematical definitions of these
vibration signals, found in Annex A of the standard, are:
| Spectrum |
 |
 |
 |
| L* |
8 |
31.5 |
0.82 |
| M |
31.5 |
200 |
1.52 |
| H |
200 |
1000 |
10.0 |
*NOTE: According to the current state of knowledge gloves
do not provide significant vibration attenuation below 150 Hz.
If it is necessary to check the vibration transmissibility at
low frequencies - e.g. for the testing of gloves purported to
provide vibration attenuation in this frequency range - then
spectrum L should be used in addition to M and H."
Other items delineated in the testing procedure are the steps
to be completed before beginning the tests, how to make the measurements
with bare hand and how to make measurements with the gloved hand.
7. EVALUATION OF RESULTS
The steps that are to be followed when calculating the mean
corrected transmissibility of gloves are:
Measurement
(3 persons) |
Location
transducer |
|
Evaluation |
|
Results
for each spectrum |
| Bare hand (once) |
handle awsRb |
 |
transmissibility
TRsb |
 |
6x corrected transmissibility |
| hand awsPb |
| With glove (twice) |
handle awsRg |
|
transmissibility
TRsg |
mean corrected transmissibility |
| hand awsPg |
The formula for calculated transmissibilities of the glove for
each vibration spectrum is:
TRs = TRsg / TRsb. The formulas used to calculate transmissibilities
for each condition are included in Section 7.1 of the standard.
To meet the criteria for antivibration gloves using this standard,
the transmissibility in the M spectrum must be less than 1 and
in the H spectrum it must be less than 0.6.
Also, to be considered an "antivibration glove"
according to this standard, the fingers of a glove must have
the same properties (material and thickness) as the palm of the
glove. However, in a note, the statement is made that gloves
not offering finger protection may still have a beneficial effect
in cases where there is no contact between fingers and the vibrating
surface.
This section on evaluation recommends that transmissibility
as a function of frequency be calculated and provides specified
frequencies to be used for third-octave bands and narrow band
analysis.
8. TEST REPORT
All items to be included in a report of the vibration transmissibility
of gloves are listed. They include: name / address of glove manufacturer,
type of glove and if new or used, description of test samples,
date of test, equipment used in test, measuring conditions, results
and name of laboratory conducting the test.
ANNEXES
Five annexes follow the text of the standard:
Annex A (normative): Mathematical definition of vibration
test signals, including Table A.1: "Cut-off frequencies
fc and constant factors c for vibration
spectra (filter slopes of 12 dB/ octave, Butterworth characteristics)"
Annex B (informative): Example of handle with gripping force
measuring systems, including FigureB.1: "Example of handle
with gripping force measuring system"
Annex C (informative): Third-octave band spectra of vibration
test signals, including Table C.1: "Spectrum M" and
Table C.1: "Spectrum H" and Figure C.1: "Spectra
M and H" (graph with Frequency and Acceleration axes)
Annex D (informative): Bibliography
Annex ZA (informative): Clauses of this European Standard
addressing essential requirements or other provisions of EU Directives.
NOTE: The International Standard on which this paper is based,
reference number
ISO 10819:1996(E), may be ordered in the United States from ANSI-American
National Standards Institute, 212/642-4900 or FAX 212/302-1286.
The publisher's address is International Organization for Standardization,
Case Postale 56, CH-1211 Geneve 20, Switzerland.
Reviews compiled and written by Chase
Ergonomics, Inc.
©1996 Chase Ergonomics, Inc.
Reproduction prohibited without express
written permission from Chase Ergonomics, Inc.
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